AUSTIN — Republican primary voters in Texas Senate District 31 have a competitive race for the first time in a decade.

Incumbent Kel Seliger of Amarillo, who first won his seat in a special election in 2004, faces former Midland Mayor Mike Canon in the March 4 election. Though more than 30 state legislators across Texas drew challengers for the March 4 Democratic and Republican primaries, the Seliger-Canon race is among the most closely watched in the state for three reasons.

First, because no Democrat is running for the seat, the winner will represent the estimated 810,000 constituents in the largely rural 37-county district for the next four years.

In addition, the balance of power in the 31-member Texas Senate is at stake, because four senators won’t return next year and two others are in tough primary races. The outgoing senators — including Democratic gubernatorial candidate Wendy Davis of Fort Worth — are running for another office or retiring.

In addition, if the Texas Tech Board of Regents appoints Sen. Robert Duncan chancellor of the university system in the spring, Gov. Rick Perry would have to call a special election to replace the Lubbock Republican.

Moreover, Lt. Gov. David Dewhurst, the presiding officer of the Senate, drew three strong Republican primary challengers. If he is ousted, the chamber would have a new leader.

And then, there is the north-versus-south factor.

If Seliger wins, the district will remain anchored in Amarillo. If Canon is victorious, the district will be based in Midland.

If re-elected, Seliger said, his priorities will be to continue working for public education, higher education, water and the repeal or state management of Obamacare, issues critical to West Texas and to the rest of the state.

Canon, an oil and gas attorney, said his priorities will be border security, education, energy, transportation and water.

Money is one key factor expected to influence the outcome of the race.

As of Jan. 23, Seliger had nearly $1.6 million in his war chest, according to campaign finance reports filed with the Texas Ethics Commission.

Canon had $77,874 left, which is less than 5 percent of what Seliger reported. In all, Canon has raised $226,000 since last year and loaned $40,000 to his campaign.

The amounts all candidates for public office raise are critical, especially in large senatorial districts such as 31.

Seliger said though he is aware Canon has not raised the amount needed for an aggressive campaign, he is a serious challenger.

This is the first serious challenger Seliger has faced since he was elected.

In the 2012 primary, Randy Rives of Odessa challenged him, but Seliger easily defeated Rives, largely because the former school board member couldn’t raise money.

District 31 is the second largest in the Legislature after SD 28, which Duncan represents. The lack of money, plus the fact that Rives is largely unknown outside the Permian Basin, crippled his campaign.

Because Canon is touting his eight-year tenure in the Midland City Council, Seliger said he hopes the voters remember he served four terms as mayor of Amarillo and as a member of Amarillo City Commission and Amarillo Civil Service Commission before being elected to the Senate.

Seliger said he also has been a successful businessman for 35 years.

Texas senators ordinarily run for four-year terms, but due to the 2011 redistricting, at the beginning of last year’s session the Senate held a drawing to determine which senators would run this year and which would get the usual four-year terms.

Seliger and 14 of his colleagues drew two-year terms, which is why he is on this year’s ballot.